Hitachi CMT2598 color TV standby ten minutes or tens of minutes automatic shutdown failure repair method -Service Manual Download|Circuit Download|Download Drawings|schematic download|route map download|free download user manual

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Hitachi CMT2598 color TV standby ten minutes or tens of minutes automatic shutdown failure repair method

Time：2014-07-28 11:08:46 Source：Network Author：Unknown Clicks：1352

Sound, determine the cause of the problem may be in the oscillation circuit.

The machine of line oscillation circuit is simpler, by video and scanning circuit IC5001 (YAT018) (28) foot external crystals X701 (CSB500F25) with the internal oscillation circuit is completed, then the line scan pulse frequency.

After replacing a CSB500F25 crystals, grating, but the images still out of sync, light is put out a few minutes later, again "3 without"; Detect IC5001 peripheral components related to the line of oscillation frequency are no exception, had to change again CSB500F25 crystals, after the change to the third little CSB500F25, finally restored image synchronization.

Summary: the failure is due to the uncertain CSB500F25 heated frequency crystal caused line output frequency change, not only out of sync, line output transformer inside a "squeak" cries, and the line output current and the change of the output pulse amplitude, the SCR Q799l into protection state.

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